The display of the reproductive behavior in most noctuid Lepidoptera follows a diel periodicity and is limited to a precise period of either the day or the night. These behavioral traits and the sex pheromone chemistry can be species specific and thus might be linked to the phylogeny. The objective of this study was to test the relationship of these reproductive traits with phylogeny. The study was undertaken using eight closely related species of noctuid stem borers, which are easy to rear under artificial conditions, namely, Busseola fusca, B...

The physiological and biochemical mechanisms that enable insects to feed on dry food to secure enough water for larval growth were investigated. The study was carried out with a plethora of physiological methods, ranging from the simple volumetric determination of O2 consumption and water intake to more advanced methods such as scanning microrespirography and thermovision imaging of insect's body temperature. The experiments were done on the European firebug, Pyrrhocoris apterus, which feeds exclusively on dry linden seeds...

Plants produce proteins such as protease inhibitors and lectins as defenses against herbivorous insects and pathogens. However, no systematic studies have explored the structural responses in the midguts of insects when challenged with plant defensive proteins and lectins across different species. In this study, we fed two kinds of protease inhibitors and lectins to the fruit fly Drosophila melanogaster and alpha-amylase inhibitors and lectins to the cowpea bruchid Callosobruchus maculatus. We assessed the changes in midgut cell structures by comparing them with such structures in insects receiving normal diets or subjected to food deprivation...

Anopheles arabiensis Patton (Diptera: Culicidae) is considered the most efficient malaria vector in eastern Sudan. This study aims to characterize the breeding sites of An. arabiensis throughout the year in and around Kassala town, eastern Sudan. Diverse larval habitat types were visited and characterized based on the habitat type and chemical composition. Mosquito larvae were found in many diverse habitats. During the rainy season, rain pools and water bodies created by the seasonal Gash River serve as the main breeding sites...

Literature is reviewed on the spatial distribution of the eggs and neonate larvae of codling moth on apple trees in relation to research conducted in Nelson, New Zealand. At Nelson, oviposition increased with height and was greater in the north and east of the trees and in those with greater fruit load in some seasons, which matches published reports. All publications and the research recorded high percentages of eggs laid singly within 10-15 cm of the fruit, with most eggs on leaves even within fruit clusters; oviposition on fruit clusters of different sizes was nonrandom because more eggs were laid on those with more fruit, but the aggregation of both per cluster and within clusters was even greater than that caused by the fruit number alone...

Mosquitoes are vectors of several human pathogens, and great attention has recently been placed on insecticides from plant-derived products, in search for mosquito control agents. This study, thus, investigated the potency of Boswellia dalzielii methanol leaf extract and its four fractions as mosquito ovicide, larvicide, and pupicide against Anopheles gambiae and Culex quinquefasciatus. The plant products were tested at the following concentrations: 125, 250, 500, 1000, and 2000 ppm on eggs and 312.5, 625, 1250, and 2500 ppm on the larvae and pupae of the mosquitoes...

The cashew stem girdler, Analeptes trifasciata, is a major insect pest of cashew in Nigeria causing economic damage in cashew plantations even at low density. In this study, newly emerged adults of A. trifasciata reared from field-infested cashew stems were collected from the rearing cages, sexed, and dissected to reveal the internal structures of the insects. The gut was excised and separated into the foregut, midgut, and hindgut. The dissected gut compartments were blotted dry by sandwiching in sterile Whatman No...

The need to have an improved knowledge on the bioecology of Culex quinquefasciatus, a prerequisite in the development of cost-effective control strategies, has informed the present preliminary investigation to put in better perspective variations that exist in the egg rafts of the species. Freshly laid egg rafts were collected and incubated at ambient temperature in well-labeled plastic trays. The results showed overall inconsistency in all indices monitored for the egg rafts. Generally, survivorship was high for the species...

Phenoloxidase (PO) is an important enzyme in insect life, which is involved in important physical functions, such as defensive encapsulation and melanization of foreign organisms and wound healing. In this study, we obtained a cDNA sequence of 2838 bp with 2049 open reading frames encoding 682 amino acids. The protein sequence deduced from the cDNA has high homology with the known PPO1 sequences of other lepidopterous insects. There were three conserved regions, including the two copper-binding sites characteristic of arthropod PPOs...

This study describes the aquatic habitats, species composition, and the insecticide resistance level of the mosquito Culex pipiens pallens in Shandong Province, China. A cross-sectional survey of mosquito larval habitats was conducted from May to November 2014 to determine the species composition and larval abundance. Larvae were collected using the standard dipping technique, and a total of four habitat types were sampled. The fourth instar larvae of Cx. pipiens pallens collected in each habitat type were tested for resistance to five insecticides according to a WHO bioassay...

The efficacy of Bacillus thuringiensis (var. kurstaki) (Btk) against the diamondback moth (DBM) on cabbage was studied at Botswana College of Agriculture, Gaborone, Botswana. Using five concentrations of Btk: 2, 4, 6, 8, and 10 g/L, bioassays were conducted against DBM eggs and second instar larvae at 30°C ± 5°C. Each treatment was replicated three times. Probit analysis was used to determine the LD50 and LD90 values for the treatments against eggs and larvae. When the treatments were assessed at 72, 96, 120, and 144 hours, LD90 values against larvae were 11...

Bactrocera cucurbitae (Coquillett) is a tephritid fruit fly native to the Indo-Malayan region. Its distribution, though, has extended to include Africa, temperate Asia, and a number of Pacific islands. It became established in Japan in 1919 in the Yaeyama Islands and spread north in the Southwestern Islands of Japan. It was subsequently eradicated from these islands by an eradication program that extended from 1972 to 1993. As part of an effort to develop a worldwide database on the status of fruits as hosts of melon fly, the infestation data gathered from host fruits collected in this eradication program, before the initiation of suppression activities, are summarized here...

Although the movement of stable fly, Stomoxys calcitrans (L.), has been studied, its extent and significance has been uncertain. On a local scale (<13 km), fly movement occurs between host animals and resting sites to feed and mate, mainly at on-farm locations where herbivorous livestock regularly congregate. Small numbers emigrate from livestock congregation sites in search of other hosts and oviposition substrate, mostly within <1.6 km. Such local movement occurs by flight ~90 cm above ground, or with moving livestock...

The present study demonstrates tissue-specific (hemolymph and fat body) and inter-voltine [bivoltine (BV) and trivoltine (TV)] differences in oxidatively damaged products, H2O2 content, and the relative level of antioxidant protection in the diapausing pupae of Antheraea mylitta. Results suggest that fat body (FB) of both the voltine groups has oxidative predominance, as evident from the high value of lipid peroxidation and H2O2 content, despite better enzymatic defenses in comparison to hemolymph (HL). This may be attributed to the higher metabolic rate of the tissue concerned, concomitant with high lipid content and abundance of polyunsaturated fatty acids (PUFA)...

Helicoverpa armigera Hübner is one of the most important agricultural crop pests in the world causing heavy crop yield losses. The continued and indiscriminate use of synthetic insecticides in agriculture for their control has received wide public apprehension because of multifarious problems, including insecticide resistance, resurgence of pest species, environmental pollution, and toxic hazards to humans and nontarget organisms. These problems have necessitated the need to explore and develop alternative strategies using eco-friendly and biodegradable plant products...